1. Field of the Invention
The present invention relates to optical-characteristic measurement apparatuses and fundus-image observation apparatuses, and more particularly, to an optical-characteristic measurement apparatus and fundus-image observation apparatus for obtaining an optical characteristic and fundus-image of an eye under measurement, respectively, by compensating a wavefront by a wavefront compensation device.
2. Description of the Related Art
Recently, optical instruments used in the medical field have been spread. Especially in ophthalmology, optical-characteristic measurement apparatuses for checking eye functions such as the refraction and adjustment of eyes and the insides of eyeballs have been spread. For example, there exists a photorefractometer for obtaining the refractive degree and the corneal shape of an eye under measurement. In a conventional eyeground observation, an eyeground was observed with adjustment performed to reduce the effect of eye aberration as much as possible.
Apparatuses which allow an apparatus optical system to be aligned with an eye under measurement by observing an eye anterior part of the eye under measurement have also been disclosed, such as those disclosed in Japanese Unexamined Patent Application Publication No. Hei-5-212002 and No. Hei-9-94230. Japanese Unexamined Patent Application Publication No. Hei-5-212002 discloses that the positional coordinates in X and Y directions of a bright-point image reflected by a cornea are detected by an alignment detection sensor, and a motor is driven based on the positional information in the X and Y directions to move the entire apparatus. With this operation, the optical axis of an apparatus optical system is aligned with the optical axis of the eyeball of the eye under measurement.
Japanese Unexamined Patent Application Publication No. Hei-9-94230 discloses that a motor is driven based on a detection signal of an X-and-Y-direction-alignment detection sensor such that an alignment bright-point image approaches the center of an automatic-imaging-allowed area, to move the apparatus body in X and Y directions. This publication also discloses that a plurality of locations in an eye under measurement can be consecutively captured after alignment is performed once.
In adaptive optics, one of issues raised when a wavefront compensation device is used in order to compensate for aberrations of a human eye is the positional movement of the eye. The eye has been fixed as much as possible by, for example, asking the person to bite a “bite bar” used in dentistry. This method imposes a burden on the person, and does not fundamentally settle the issue of how to fix the position of the eye. Since the apparatus itself is moved in each of Japanese Unexamined Patent Application Publication No. Hei-5-212002 and No. Hei-9-94230, the apparatuses are not suited, for example, to a case where a high magnification is used.